A very common scenario for an XFCE desktop is to have network (Wi-Fi usually) managed by NetworkManager, which means network is only available some time after logging in. Mailwatch plugin usually loads faster, especially with Wi-Fi or DHCP, which means it always gives an unnecessary error on startup, which actually shouldn't be an error, misleads the user and grabs its attention unnecessarily and delays actual check . This is all the more annoying since any later actual error is not going to be identified as such unless the user clears the first non-error manually, which is tiresome and annoying.

I understand therefore that mailwatch plugin should wait until a network connection is available before checking for messages on startup. A typical schema is waiting by increasing powers of two until network is available. If it is deemed necessary or advisable to let the user know that mail hasn't been checked yet because of network unavailability (and not that it was checked and there was actually no new mail), the status envelope could be brighter (whiter) and have dashed lines until network is detected. I think it can be assumed that there should be a suitable network ready when there is an interface up that can route to the mail server address, and there is a name server set and an interface up that can route to it if mail server is not numeric.